Antiseptic effect of low-concentration povidone-iodine applied with a depot device in the conjunctiva before cataract surgery

PURPOSE: Examine the antiseptic effect of long-term low-concentration (0.3%) povidone-iodine (PI) before cataract surgery. SETTING: St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway. DESIGN: Single-armed prospective clinical study. METHODS: Repeated measure of preoperative conjunctival samples from 51 participants were obtained the day before surgery (T1), the day of surgery after treatment with ophthalmic NSAID (T2), and after additional treatment with low-concentration PI (T3) given by placing a pledget soaked in a mix of eye-drops in fornix inferior for 20 min. RESULTS: Before surgery, and before any type of treatment (T1), bacterial growth (≥5 BC) in the conjunctiva was identified in 36 (66.7%) of the participants. After treatment with ophthalmic NSAID (T2), and after additional treatment with low-concentration PI (T3), bacteria were identified in 31 (60.8%) and 12 (23.4%) participants, respectively. All except one of the participants with a measurable change from T2 to T3 (n = 31, 60.8% of total sample), experienced a decrease in number of bacterial colonies (BC) after treatment with low-concentration PI (96.8 vs. 3.2%, p < 0.001). A complete removal of bacteria was seen in 20 (n = 31, 64,5%) of the colonized participants after treatment with PI. CONCLUSIONS: Preoperative treatment with long-term, low-concentration PI applied via a depot device in fornix inferior, seem to be an easy and effective way to reduce the number of BC in the conjunctiva.